Try a subtle yet direct approach. Try for instance:
You: Do you know what they do to a a javelin?
Friend: Throw?
You: Correct. And so do you!
-)
"Even Miraa has an expiry date. Check under the leaves!"
http://geocities.com/roomthinker
LOL, OR just be straight with her and tell her that she is so smelly, even a boomerang wouldn't return to her.